Growing with Groen: Potatoes

“PO-TA-TOES! Boil ‘em, mash ‘em, stick ‘em in a stew.” At last we come to it, the article I’ve desired to write since I began this column. It is on, of course, potatoes.

The potato plant, Solanum tuberosum, produces potatoes. This delicious tuber is a modified “rhizome”, or underground stem, and is used for energy storage. Underground storage structures are a common adaptation among herbaceous plants that evolved in seasonally cold climates. Secreted below soil, away from ice and frost, the underground tuber holds the starches the perennial plant uses to sprout new shoots each spring­­—likely you’ve seen this phenomenon happen when potatoes sit too long.

Like most other normal humans, nearly every day I have eaten at least a pound of potatoes in various forms. Globally, one billion people eat 300 million metric tons of potatoes a year; I must be normal. Yet, unlike some other plant-made food, a potato has a considerable predilection that you not to eat it. Furthermore, domestication involved serious hurdles: the potato plant was, and can still be, poisonous.

Potatoes are a luxury taken for granted. Let me explain.

A potato is no fruiting body. The Russets, Reds, and Yukon Gold you eat are a critical structure used by the plant. They contain the energy required to fuel sprouts on their push out of soil and into the light. Their loss threatens the short term life of the individual and, by association, the existence of the species. Regardless, potato removal requires digging the plant up; harvesting kills the plant. Thus, picking potatoes is much more calamitous to the potato plant than, say, picking an orange from a tree or pod for a pea.

Potatoes evolved a solution: solanine produced in their tissue. Ingesting this chemical can cause mild deliria and intestinal distress. Potatoes that are turning green can sometimes produce solanine, or other glycoalkaloids. You may be able to eat green eggs and ham, but I wouldn’t eat green potatoes without significantly cooking them. Unsurprisingly, potatoes come from a family known for its harsh, noxious compounds: the Solanaceae, or Nightshade Family.

To reach the potato we eat today, generations of persistent selection and breeding had to occur to obtain a potato sans-solanine. It is the product of years of work and a luxury taken for granted.

A potato had never been seen in Europe until the discovery of the New World. Indigenous to the Andes Mountains, Europeans propagated only select varieties of the 4,300 available (Google search images, some are crazy). In Ireland, just one variety was grown: the “Lumper.”

Exacerbating the issue, propagation through vegetative splitting resulted in clonal monocultures. Low genetic diversity led to a sad story to which everyone knows the end.

The potato has been a source of both elation and angst. It is the third most grown crop, behind corn and wheat. It is highly efficient, and relative ease, of growth make the potato affordable to millions who would waste with hunger otherwise. With so much hope placed in the potato, a crop failure can utterly demoralize humanity and be quite dangerous.

Thankfully, humanity has not lost hope in the potato. I, for one, never will.